/Engine/Source/Runtime/CoreUObject/Public/UObject/UnrealType.h
What this function does is tries to make this stuff a lot more human readable, by printing, ActionsArray[3].ActionIfo.ActionPower, so that you know the index it comes from. Similarly Maps would print ActionMap["Action Name"].ActionIfo.ActionPower, so that you know the index it comes from. Similarly Maps would print
[FString](API\Runtime\Core\Containers\FString) GetPropertyPathDebugString() const